> But anybody who edited a 100 000 lines long project, ran the unit test, and saw red lines, fixed them, ran it again and then saw green now the feeling : it's

> But anybody who edited a 100 000 lines long project, ran the unit test, and saw red lines, fixed them, ran it again and then saw green now the feeling : it's great. You are way more confident. This is the key insight: unit tests are about feelings more than anything else. People get so defensive in unit testing threads because eliminating unit tests means eliminating their source of confidence.